#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
    int a,b,c;
    while(scanf("%d %d %d",&a,&b,&c) != EOF)
    {
        if(a + b > c && a - b < c)
        {
            if(a == b && a == c)
            {
                printf("Equilateral triangle!\n");
            }
            else if(a == b || b == c || a == c)
            {
                printf("Isosceles triangle!\n");
            }
            else
            {
                printf("Ordinary triangle!\n");
            }
        }
        else
        {
            printf("Not a triangle!\n");
        }
    }
    return 0;
}



